Reason for 64bit
#1
Hello,

As a long-time Raspberry Pi fan I jumped on this, mainly because I just wanted to have a bit of a play around.

Once these are delivered , I'm sure people will find many uses for them but I was wondering for what applications the 64-bit part actually is useful given the memory limitations. I write a lot of code but I practically never have to worry about 32-bit / 64 - bit as the libraries I use are available in both. It is onyl useful to me because I find more than 4 GB RAM very useful. 

I didn't find any threats here on the specific uses for the 64bit-ness, so if there are some I missed, please link.
#2
Well, even though 1 or 2GB of DRAM fits easily into a 32-bit memory address space, on linux you can map files to memory regions, so an application can use more than 4GB of address space while still consuming less than the total DRAM. Consul and cassandra are two examples of such applications. And of course, you could have a swap partition > 4GB if you wanted (although even an SSD over USB2 probably wouldn't be fast enough to make paging large regions useful).
#3
(03-01-2016, 11:45 PM)patrickhwood Wrote: Well, even though 1 or 2GB of DRAM fits easily into a 32-bit memory address space, on linux you can map files to memory regions, so an application can use more than 4GB of address space while still consuming less than the total DRAM.  Consul and cassandra are two examples of such applications.  And of course, you could have a swap partition > 4GB if you wanted (although even an SSD over USB2 probably wouldn't be fast enough to make paging large regions useful).

I never thought of that, indeed. Odd considering that RAM is a major limitation for lots of the computations that are run in my group. Anyways, thanks for the response!
#4
CNXSoft has a post about the difference in performance between ARM 64 bit and 32 bit instructions:
http://www.cnx-software.com/2016/03/01/6...tructions/
So there is increase in performance going from 32 bits to 64 bits probably since the data bus and CPU registers are larger.


Forum Jump:


Users browsing this thread: 1 Guest(s)